Malicious PDF — malware analysis report

Static analysis result for SHA-256 10b99d1358d58555…

MALICIOUS

PDF

92.7 KB Created: 2021-07-15 11:02:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: eec9c61b167c7cf5e5ebfc555eed5287 SHA-1: 93489d7dc0a3b4ba8ed8f0076857004074a9b314 SHA-256: 10b99d1358d58555822b2c632e76f67e6f5522e7a68da76bd8cb1ec9176402f3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs point to compromised CMS uploads and disposable hosting, indicating a likely phishing or malware distribution scheme. The document body is heavily obfuscated and unreadable, providing no direct clues to its intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9924

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://www.franklinwebdesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce93dbd23b---pedajobebofadogam.pdf In PDF document text
    • http://esipro.fr/userfiles/file/rijuzazumisomadodonasul.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16078990982e5b---paluwipal.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1607bcd99b9340---nodogimim.pdfIn PDF document text
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/e34f3f69a2a939cd3eaa171c7471132a/60989567399.pdfIn PDF document text
    • http://quincy.pl/ckfinder/userfiles/files/46883120103.pdfIn PDF document text
    • https://grafitpoint.ru/wp-content/plugins/super-forms/uploads/php/files/3f49821f736d03ae4a31c49a9b5c0c35/jeduravipasedopifokifape.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/6qj53rl1d92r235usglebp2cj3/71027014432.pdfIn PDF document text
    • http://enjoy.sk/editor_uploads/system/files/67325500897.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/f66d3c974ea0b85525133d4fc94e276e/naduzikalumibavupuvagun.pdfIn PDF document text
    • http://rajskiewakacje.pl/userfiles/file/lomezanul.pdfIn PDF document text
    • http://satbietthu.com/luutru/files/kibemigafubufadon.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c28bb58e60f---74918246184.pdfIn PDF document text
    • https://hondamienbac.vn/userfiles/file/derevejoxubap.pdfIn PDF document text
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607b2041a353d---zaxoj.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/89468dklpq72dm7r1rnfrtvfm0/29794105458.pdfIn PDF document text
    • http://travelport.pl/userfiles//file/nagugajubuvotezatezowuna.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7e06894ae3---56666599451.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a15d49784d0---jujuluwejitaz.pdfIn PDF document text
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/46d73bf9f1ebc7411bec263201d26d59/16223869538.pdfIn PDF document text
    • https://www.projectorrentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071a89186fb7---wusokawuzo.pdfIn PDF document text
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606d5112f2592---depozesaxetilejap.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160824e5b023f4---foxikejinofejeben.pdfIn PDF document text
    • https://www.endthestigmacounselling.com/wp-content/plugins/super-forms/uploads/php/files/rnum59nkml6gtuap66p4lp9ruc/biguj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=he+is+superior+than+me+correct+the+sentencePDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ee89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE89 16400 bytes
SHA-256: b4c78cc6e5c2960eab4c85e13f7ceeee32fbf3afecd474ad803e35c5d6624684
font_01_sfnt_off00010511.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10511 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011d28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D28 10684 bytes
SHA-256: ef8b72bb8b0d27c77d2fdfde083c220f395d98736101a678f1e02a2d2a80bcfb
font_03_sfnt_off00013574.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13574 17896 bytes
SHA-256: 63b8853a6ec1602ecaf07a816cba09e4b6a414642c12ff8738b8c96bb9b221de